452 DILLEK AND STANTON THE SHASTA-CHICO SERIES. 



the same section, are conformable throughout/'^ and the character of the 

 sediments is also the same. There can be no further doubt croncerning 

 the continuity of life throughout the series. Several successive faunas 

 are recognizable, but they are all closely bound together by many com- 

 mingling species. The Shasta-Chico series, including the Wallala beds, 

 may therefore be considered as a unit in discussing the geology of the 

 Pacific coast. 



There is, however, one other argument for its unity to which it is de- 

 sired to call attention. On the eastern side of the Sacramento valley the 

 Chico beds rest with a conspicuous unconformity directly on the meta- 

 morphic rocks of the auriferous series. About the northern end of the 

 Sacramento valley the same is true, but as we move southwestward from 

 Redding, along the foot of the Klamath mountains and Coast range, we 

 find successively older and older beds coming in below and resting with 

 this marked unconformity on the metamorphic rocks. At Texas springs 

 and Horsetown this great unconformity runs beneath the Horsetown 

 beds. Farther south, on Cold fork and elsewhere, the same great uncon- 

 formity runs beneath the Knoxville beds, so that the Chico, Horsetown 

 and Knoxville beds all hold exactly the same relation to the great uncon- 

 formity of that region, and thus furnish additional evidence that they 

 belong to the same series. 



Distribution of the Series. 



The unity of the Shasta-Chico series being admitted from the evidence 

 already adduced, several consequences of importance follow from the 

 vertical and horizontal distribution of the series. 



An examination of these deposits in the field shows clearly that the 

 Horsetown beds overlap the Knoxville northward along the western side 

 of the Sacramento valley, and the Chico beds in like manner overlap the 

 Horsetowm in the same direction, so as to reach not only the western 

 base of the Sierra Nevada, but extend northeastward between the Sierra 

 Nevada and Klamath mountains far into Oregon, connecting, in all 

 probability, with the Chico of the Blue mountains in that state, as well 

 as with that of Washington, Vancouver and Queen Charlotte islands. 



In Oregon also, as already noted in California, the Horsetown beds 

 overlap the Knoxville, well exposed in the vicinity of Riddles, in Douglas 

 county, and extend as far southeastward as Graves creek, where thev rest 



*Mr Fairbanks recognizes a small unconformity between the Knoxville and Chico beds, due to 

 the eruption of the peridotitic rocks from which the serpentine has been derived (Eleventh Re- 

 port state Mineralogist of California, p. 67; also American Geologist, March. 1892, p. 166) ; but the 

 great unconformity which Dr Becker (U. S. Geol. Survey, Bulletin no. 19, p. 12) places at this hori- 

 zon belongs below the Knoxville. 



